The outrage was sparked by the fate of Oleg Shcherbinsky, a railway worker from Siberia, who was jailed for four years last week for failing to yield to a speeding Mercedes carrying Mikhail Yevdokimov, the regional governor.
The limousine careered off the road and into a tree, killing the governor.
Across Russia this weekend, thousands of people are planning to protest by driving in convoy through major cities with slogans including "Today it's Shcherbinsky. Tomorrow it will be you!" draped on their cars.
The case has brought to the boil simmering anger at a two-tier system that allows bureaucrats in chauffeur-driven black limousines to weave dangerously through traffic while other motorists are fined for the smallest misdemeanour.
Some say it is a metaphor for Russian society in general under President Vladimir Putin where a narrow class of bureaucrats enjoy increasing power while, critics say, ordinary peoples' rights are undermined.
Critics say Putin's policies
have created a two-tier society
Vyacheslav Lysakov, is head of the "Freedom of Choice" motorists' lobby group that is helping organise the protests.
"It is time to stop dividing people into first-rate citizens and third-rate, into serfs and nobles," he said.
Shcherbinsky's supporters in his home city of Barnaul are planning a rally on Saturday. Protests are planned in cities from Moscow to Vladivostok on the Pacific Coast on Sunday.
"Every person in Russia understands they could easily find themselves in Oleg Shcherbinsky's shoes," said Vladimir Ryzhkov, an opposition member of parliament who represents Barnaul.
"People are upset that bureaucrats break the rules and an ordinary person ... through no fault of his own, gets four years in prison. That is why there has been such an uproar."
There are thousands of government cars on Russian roads, marked out by special licence plates and a flashing blue light on the roof, nicknamed a "migalka", which means a winker.
Carrying on a tradition since Soviet times, they routinely jump traffic lights, avoid queues by driving into oncoming traffic and break the speed limit.
Other common practices are parking illegally and driving along pavements. Traffic police nearly always ignore them.
On 7 August last year, Shcherbinsky, 36, was driving with his family to a local beauty spot in his second-hand Toyota Marino.
"It is time to stop dividing people into first-rate citizens and third-rate, into serfs and nobles"
Motorists' lobby group
He indicated, then turned left off the main road. Yevdokimov's car, travelling in the same direction, came over the brow of a hill. It swerved to avoid the Toyota but clipped it and hit the tree. The governor's driver and bodyguard were also killed.
Police told the trial the Mercedes' speed was not less than 149 km an hour.
Shcherbinksy's lawyers said it was travelling at 200 km an hour.
The court ruled that Shcherbinsky should have seen the Mercedes behind him and let it pass as it had a "migalka."
Shcherbinksy's lawyers are preparing an appeal, said Andrei Karpov, one of his legal team. He said the court had set out from the start to find Shcherbinsky guilty.
"The court took the side of officialdom, and not the side of justice," Karpov said.